1. Field of the Invention
The present invention relates to a roof rail air bag assembly for a vehicle and a method of attaching same.
2. Background Art
Use of roof rail air bag assemblies, used primarily as a means to protect vehicle passengers, is well known. Likewise, methods of attaching these air bag assemblies are also well known. Despite their widespread use, typical attachment mechanisms have inherent limitations.
One limitation is the necessity of having separate fasteners to attach the air bag assembly to the vehicle. U.S. Pat. No. 6,082,761 (Kato et al.), issued Jul. 4, 2000, discloses an air bag assembly containing a bracket with mounting holes. Separate fasteners, either threaded or push-in, are inserted through the mounting holes and then secured to the vehicle. This type of design increases the cost of the air bag assembly by requiring additional partsxe2x80x94i.e., fastenersxe2x80x94as well as the additional labor required to install the fasteners and mount the assembly to the vehicle from the side or overhead. Alternative fastener designs include the attachment of weld nuts or xe2x80x9cu-nutsxe2x80x9d to the roof rail to provide for the air bag installation. Each of these designs however, incurs the additional cost of separate fasteners.
One attempt to overcome this limitation is disclosed in U.S. Pat. No. 5,988,735 (Muller), issued Nov. 23, 1999. Muller discloses a vehicle head liner into which air bag assemblies are mounted. This eliminates the need to separately mount the air bag assemblies onto the vehicle. With this design, the air bags are installed into the vehicle when the head liner is installed, thus eliminating the need to use separate fasteners. A disadvantage of this design is that the installation of the head liner is made more difficult because of the presence of the air bag assemblies. Moreover, this design, as well as other prior art designs, all have another inherent limitation: overhead installation. Each of these designs requires operators to work with air bag assemblies over their heads, which increases overall cycle time.
Accordingly, it is desirable to provide an air bag assembly which overcomes the above referenced short comings of prior art air bag assemblies, by eliminating the need for external fasteners as well as the need for the operator to enter the vehicle or work overhead.
The present invention provides an air bag assembly that can be attached to the roof rail of a vehicle without the use of external fasteners and while the operator is standing outside the vehicle. This device has applications to all vehicles designed with a modular roof system. The modular roof system is one in which the roof of the vehicle remains open during much of the vehicle""s assembly, and then at a later stage, a roof panel is attached covering the opening. This allows the air bag assembly to be hung from the roof rail with the operator standing outside the vehicle and reaching through the vehicle roof opening. After the roof panel is installed, the hanger is trapped between the roof panel and the roof rail, thereby permanently attaching the hanger to the vehicle.
In a preferred embodiment, an air bag module containing an air bag and an inflator is mounted to a hanger to create a roof rail air bag assembly. The hanger is approximately xe2x80x9cCxe2x80x9d shaped, with a top and bottom portion which are approximately horizontal, connected by a side portion that is angled to accommodate the roof rail. The bottom portion includes a hole to receive a threaded fastener, and the top portion includes a tab, designed to cooperate with an opening in the roof rail.
The hanger is attached to the air bag module with the threaded fastener and a mating nut. Depending on the length of the air bag module, more than one hanger may be used. The air bag module and the hanger, now secured to each other, create a complete roof rail air bag assembly. This is received by the installing operator as a complete unit.
With the preferred embodiment, the roof rail of the vehicle will have a slot, approximately rectangular in shape, pre-formed in its top. It is then a simple matter for the operator, standing outside the vehicle, to place the complete roof rail air bag assembly through the roof opening and pull it back towards the roof rail. The tab on the hanger slides into the slot in the roof rail, while the air bag module slides into position under the roof rail.
In an alternative embodiment, the hanger is designed to accommodate the larger air bag modules associated with sport utility vehicles and the like. A single hanger is made wide enough to include a plurality of tabs. In this way, the top portion of the hanger contacts much more of the roof rail, thereby providing additional support. Moreover, the bottom portion is wide enough to provide multiple points of attachment for the air bag module.
In another embodiment, the hanger does not have a tab, but rather a push-in fastener, such as a xe2x80x9crosebud clipxe2x80x9d. This design necessitates a change in the roof rail as well, such that the approximately rectangular slot is now replaced with a hole. Attachment of the hanger to the air bag module is the same as in the preferred embodiment, and again the operator receives the complete roof rail air bag assembly as one unit. With this embodiment, the operator again places the assembly into the vehicle through the opening in the roof, and pulls it toward the roof rail. Then, as the air bag module slides into location below the roof rail, the push-in fastener slides toward the hole in the top of the roof rail. Once the push-in fastener is aligned with the hole, the operator can push it into place.
Each of these embodiments are installed by an operator standing outside the vehicle, with no need for the operator to work in an overhead position. Moreover, no loose fasteners are used by the operator, since the roof rail air bag assembly is received as a complete unit. Finally, at a later stage of vehicle assembly, a roof panel will be secured to the top of the roof rails, thereby permanently trapping, thus attaching the hanger to the vehicle. Should the air bag module ever need service, it merely involves removing the threaded fastener and the nut from the hanger. This allows the air bag module to be removed, while the hanger itself remains trapped between the roof panel and the roof rail, and therefore remains permanently secured to the vehicle.
Accordingly, it is an object of the present invention to provide an air bag assembly that can be installed in a vehicle roof rail without the need for the installing operator to work overhead or use separate fasteners.
It is a further object of the present invention to provide an air bag assembly that can be installed in a vehicle roof rail by an operator standing outside the vehicle, whereby the assembly has a hanger, initially attached to the roof rail by the operator, then permanently attached when a roof panel is installed.
A more specific object of one aspect of the invention is a roof rail air bag assembly for a vehicle which has a roof panel and a roof rail. The assembly comprises an air bag module, having at least an air bag and an air bag inflator. A hanger is attached to the air bag module and has a top portion and a bottom portion connected to each other by a side portion, wherein each of the portions has an inner surface and an outer surface. An attachment device is located adjacent to the inner surface of the top portion of the hanger, and is capable of cooperating with the roof rail and the roof panel for attaching the air bag assembly to the vehicle.
A more specific object of another aspect of the invention is a method of installing a roof rail air bag module on a vehicle having a roof rail with an opening and a roof panel, without entering the vehicle and/or working overhead, which comprises providing the module with a hanger portion having an attachment device which is attachable to the roof rail from outside the vehicle, and trapping the hanger portion between the roof rail and the roof panel by attaching the roof panel to the roof rail from outside the vehicle.
A more specific object of yet another aspect of the invention is a vehicle having a roof opening which comprises a roof rail having a top portion and a bottom portion at least partially defining the roof opening, wherein the roof rail has an opening in the top portion. The vehicle has a roof rail air bag assembly comprising at least a roof rail air bag module and at least one hanger, wherein the hanger has an attachment portion, a roof panel configured to cover the roof opening and securable to the roof rail, and wherein the air bag module is located under the bottom portion of the roof rail, the hanger attachment portion is securable inside the roof rail opening, and the roof panel is secured to the roof rail, thereby trapping the attachment portion of the hanger between the roof panel and the roof rail.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.